The BQS Control is essentially the same as the BQC Control but the bass
and treble controls are on separate pots. The mid-control is concentric
(stacked). This active EQ circuit for bass guitars works by rotating the
control clockwise to boost, counterclockwise to cut. There is a center
detent for flat response. The mid-range control has a variable frequency
knob that allows you to sweep through the mid-frequency range from
100Hz to 1KHz. This selects the frequency to boost or cut. The BQS
Control will also work with active or passive pickups. 2 extra volume
knobs are included.